能谱CT对下肢血管血栓与非钙化斑块鉴别的应用价值

Application of energy spectral CT in differentiating thrombus from non-calcified plaque in lower limb vessels

目的探讨下肢血管病变中血栓与非钙化斑块的能谱CT参数差异,探究鉴别两者的参数及其诊断效能。方法回顾性收集行下肢能谱CT检查且1周内完成DSA手术的81例病人,共纳入109处血栓或非钙化斑块病变进行分析。根据DSA结果将病变分为血栓组(34处)与非钙化斑块组(75处)。在能谱CT上测量并记录能谱参数,包括能谱曲线斜率(λ)、有效原子序数(Eff-Z)、钙水物质密度[Ca(W)]、碘水物质密度[I(W)]、水碘物质密度[W(I)]、水钙物质密度[W(Ca)]、70keV下的CT值(CT_(70keV))。采用独立样本t检验、Mann-WhitneyU检验、χ^(2)检验比较2组间参数,对差异有统计学意义的参数进行多因素Logistic回归分析,采用受试者操作特征(ROC)曲线评价能谱参数的诊断效能。结果血栓组病人的急性病程和房颤占比均高于非钙化斑块组,高血压和冠心病占比低于非钙化斑块组(均P<0.05)。血栓组中能谱曲线斜率(λ)、W(I)和W(Ca)均高于非钙化斑块组(均P<0.05)。多因素Logistic回归结果显示病程、冠心病、房颤、λ、W(I)和W(Ca)是鉴别血栓与非钙化斑块的独立预测因子(P<0.05),其中,病程的AUC(0.860)和敏感度(85.3%)最高,房颤和W(Ca)的特异度最高(98.7%),λ、W(I)和W(Ca)的截断值分别为0.65、1052.08、1048.89,值越大越倾向于血栓的诊断;联合参数[病程、房颤、λ、W(I)和W(Ca)]AUC为0.929,敏感度为88.2%,特异度为90.7%,诊断效能高于单一参数。结论在下肢血管病变中,能谱CT参数对血栓与非钙化斑块有鉴别意义,同时结合临床病史,可为临床术前病变成分预判及术式选择提供帮助。

Objective To explore the differences in energy spectrum CT parameters between thrombus and non-calcified plaques in vascular lesions of the lower extremities and to investigate the parameters and diagnostic efficacy for distinguishing between thrombus and non-calcified plaques.Methods We collected data from 81 patients who underwent lower limb energy spectrum CT examinations and completed DSA operations within 1 week.A total of 109 lesions,either thrombus or non-calcified plaque,were included for analysis.Based on the DSA results,the lesions were divided into thrombus group(n=34)and non-calcified plaque group(n=75).We measured and recorded energy spectrum parameters on energy spectrum CT,including slope of energy spectrum curve(λ),effective atomic number(Eff-Z),density of calcium water[Ca(W)],density of iodine water[I(W)],density of water iodine[W(I)],density of water calcium[W(Ca)],and CT value under 70 keV(CT_(70 keV)).Independent sample t test,Mann-Whitney U test andχ^(2) test were used for comparison between the two groups.Multivariate logistic regression analysis was used to analyze the parameters with statistically significant differences.We used receiver operating characteristic(ROC)curve to evaluate the diagnostic efficiency of energy spectrum parameters.Results The thrombus group had a higher proportion of acute cases and atrial fibrillation compared to the non-calcified plaque group,while the proportion of hypertension and coronary heart disease was lower in the thrombus group(all P<0.05).Theλ,W(I)and W(Ca)in the thrombus group were higher than those in the non-calcified plaque group(all P<0.05).Logistic regression analysis showed that the course of disease,coronary heart disease,atrial fibrillation,λ,W(I),and W(Ca)were independent predictors for distinguishing thrombus from non-calcified plaque(P<0.05).Among them,the course of disease had the highest AUC(0.860)and sensitivity(85.3%),while specificity(98.7%)was the highest for the atrial fibrillation and W(Ca).The optimal critical values for theλ,W(I),and W(Ca)were 0.65,1052.08,and 1048.89,respectively.The larger the value,the more inclined to the diagnosis of thrombus.A combined parameter[course of disease,atrial fibrillation,λ,W(I),and W(Ca)]had an AUC of 0.929,sensitivity of 88.2%,and specificity of 90.7%,outperforming individual parameters.Conclusion In vascular lesions of lower extremities,energy spectrum CT parameters play a significant role in differentiating thrombus from non-calcified plaque.When combined with clinical history,they can provide valuable assistance in predicting lesion components and selecting appropriate surgical methods before clinical operations.